Winding Magnetic Field and Short Circuit Strength Calculation of 40000KVA Power Transformer

Based on the short-circuit calculation, there is still no unified method. In order to accurately analyze the short-circuit resistance of the power transformer, refer to the evaluation method given by the national standard, take a 40,000KVA power transformer as the research object, and adopt the finite element method to the transient axis under the transformer short-circuit condition The symmetrical field is calculated, and the amplitude and axial leakage flux density of different heights of the winding is analyzed. On this basis, combined with the calculation method of the short-circuit strength of the winding, considering the cumulative effect of the winding, the stress of the winding and the change rule of the short-circuit force of the medium-voltage and high-voltage winding is calculated, and the strength criterion of the winding is given. Finally, the leakage magnetic field and force of the prototype were tested to monitor the short circuit process and compared with the calculation results, showing the accuracy of the calculation method.